Cita APA

 Babbie, E. (1990).  Survey research methords.  Wadsworth Pub. Co.

Chicago Style Citation

 Babbie, Earl.  Survey Research Methords.  Wadsworth Pub. Co, 1990.

Cita MLA

 Babbie, Earl.  Survey Research Methords.  Wadsworth Pub. Co, 1990.

Atenció: Aquestes cites poden no estar 100% correctes.